My neighbour has been given a car by her family which has stood for a considerable time under a Sycamore tree. She asked me to pressure wash it down which I duly did and also a good soapy wash down and rinse. When I tried to chamois it down after it was still very sticky and instead of the chamois removing the water marks it has left streaks with fine bits of chamois powder mixed in. Any suggestions how to get rid of the sap other than repeated washing?

Richard